Pressure vacuum release hermetic valve for rigid container packages

ABSTRACT

A rigid container package, such as made of tin, metal, etc., having an interior for holding particulate material, such as food stuffs (like coffee beans), under vacuum, and which includes a mouth to be opened to provide access to the contents of the package. The package is preferably formed from a rigid material in the form of a container, such as a tin box, and has affixed thereon a one-way pressure-equalizing valve. The valve preferably includes a displaceable rubber disk located on a valve seat and is arranged to operate such that any gasses within the package are allowed to vent to the exterior of the package, by passing through the interface between the disk and valve seat, while the ambient atmosphere is substantially precluded from entering into the interior of the package. The disk then engages the valve seat to isolate the interior of the package from the exterior. A layer of silicone oil or similar material is preferably provided on the disk to facilitate operation of the valve. The valve is preferably attached to the rigid container via an aperture that is made slightly smaller than the exterior mating portion of the valve, such that the smaller portion of the valve can be passed through the aperture, and the expanded portion of the valve can then be allowed to firmly rest against the exterior of the rigid container material, wherein friction between the container and valve (resulting from an interference fit) helps to seal the aperture and adhere the valve to the rigid container.

RELATED APPLICATION

[0001] The application claims the benefit of the filing date of U.S. provisional patent application, serial no. 60/452,499, filed on Mar. 7, 2003.

BACKGROUND OF THE INVENTION

[0002] This invention relates generally to rigid container packages, such as made of tin or metal, etc., and more particularly to rigid container packages for holding products in a hermetically sealed condition, e.g., isolated from the ambient atmosphere.

[0003] Various types of rigid container packages for holding particulate material under vacuum therein are commercially available today.

[0004] The major advantages of rigid container packaging, as compared to relatively flexible packaging, e.g., paper, foil, paper cartons, etc., are that rigid containers store more uniformly and are typically stronger than flexible packaging. These are significant advantages insofar as retail sales are concerned. They are also very well known and accepted throughout the packaging industry and have been for over 100 years.

[0005] One common type of rigid container package holds goods under vacuum until the package is opened. This is the so-called “coffee tin” package. Typically, such a package is formed from tin, metal or other rigid container stock material, into a tubular or square body, such as in various sizes, and is formed by machine to create a “sealed” canister.

[0006] One-way degassing valves are sometimes included in flexible packages to enable gasses produced by the particulate material within the package, such as coffee beans, to exit from the package, while preventing outside air from entering into the package through the valve. Examples of such one-way degassing valves are shown in U.S. Pat. Nos. 3,595,467, 3,799,427 and 4,420,015, which are incorporated herein by reference.

[0007] One drawback of many flexible packaging, such as commercially available vacuum sealed flexible packaging, is that when the packages are filled, sealed and evacuated, the walls can intimately engage the particulate material therein, which can result in an uneven, bumpy, pebbly or otherwise less than satisfactory aesthetic appearance. Another drawback is that in retail packaging, flexible containers are easily broken, such as when dropped by the customer, or damaged in shipping, thus potentially creating a dirty, ugly environment. This can be especially undesirable when the flexible container is broken or dropped in a supermarket aisle, and its content spilled onto the floor, which happens regularly.

[0008] Tin boxes, on the other hand, always provide a smooth, non-bulging aesthetically pleasing appearance, while enabling the package to be vacuum-sealed to keep the contents fresh. They also cannot be broken, torn, ripped, etc., thus creating a much stronger and more ideal vehicle to package fresh sensitive goods.

[0009] Accordingly, a need exists for packaging that is simple in construction, relatively low in cost to produce, and provides the advantages of conventional hermetically sealed packaging, but which has a one-way degassing valve, and is constructed from an aesthetically pleasing rigid material, so that the container has a smooth, non-bulging external appearance, that can be printed on for an aesthetically pleasing retail appearance, and that is easy to fill, easy to stack, and which constitutes standard and commonly acceptable packaging.

SUMMARY OF THE INVENTION

[0010] The present invention relates to a substantially rigid package container, e.g., made of tin, metal or other substantially rigid material, having an interior for holding a particulate material, e.g., dry pet food, coffee, chemicals, etc. The package is preferably a box-like container formed from tin, metal or other rigid material and comprises walls or panels, inside of which defines an open-able mouth for the package, along with a re-sealable lid. The package preferably includes a pressure/vacuum release hermetic degassing valve in one portion thereof, such as on one of its panels. The package is hermetically sealed to isolate its contents from the ambient surroundings.

[0011] The valve is arranged to operate as follows: The valve allows any gasses within the package to gain egress from the interior to the exterior of the package, while precluding the ambient atmosphere from gaining ingress into the interior of the package. Any gasses produced by the contents of the package, therefore, can vent out of the valve to the ambient surroundings, while any outside air is prevented from entering into the package, thus keeping the contents as fresh as possible.

[0012] In accordance with one preferred aspect of the invention the valve includes a displaceable member, e.g., a planar resilient-material disk or substantially flat member or membrane, arranged to be disposed on a valve seat, to be lifted therefrom when the pressure within the package exceeds the pressure outside the package.

[0013] A layer of a viscous fluid, e.g., silicone oil, is preferably provided on the displaceable member, e.g., the disk, so that the fluid is located at the interface of the disk and valve seat. The presence of this fluid provides tension to the disk which can prevent any penetration of air through the interface, but which allows the disk to separate from the valve seat when the pressure differential is high enough, i.e., when the pressure in the container exceeds the pressure outside the container.

[0014] The valve is preferably attached to the rigid container via an aperture that is made slightly smaller than the exterior mating insert portion of the valve, such that the smaller portion of the valve can be passed through the aperture, and the expanded portion of the valve is then allowed to firmly rest against the exterior of the rigid container material, wherein friction between the container and valve (resulting from an interference fit predominantly between the insert portion and aperture) can be used to permanently seal the aperture and adhere the valve to the rigid container.

[0015] Accordingly, it is a general object of this invention to provide a rigid container package, which addresses the needs of the prior art.

[0016] It is a further object of this invention to provide a rigid container package for particulate material formed from tin, metal or other rigid container material, which can be hermetically sealed, yet which exhibits a smooth, non-bulging or concaving exterior appearance.

[0017] It is a further object of this invention to provide a hermetically sealed tin, metal or other rigid container package for particulate material, which includes a degassing valve to permit the package to reach an equilibrium state in which the pressure within the package is equal to the pressure outside the package, without allowing exterior air to enter into the package.

[0018] It is a further object of this invention to provide a hermetically sealed rigid container package, which is simple in construction, relatively low in cost, which can be manufactured easily and which provides an aesthetically pleasing appearance.

[0019] It is a further object of this invention to provide a hermetically sealed rigid container package for particulate material which includes a degassing valve to enable the release of gas from the interior of the package so it that can be readily stacked without fear of explosion or bursting, bulging or convexing of the rigid container.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a representation of a cross section of a typical tin box having a degassing valve attached thereto on the bottom floor thereof;

[0021]FIG. 2 is a cut-away side view of the degassing valve positioned and secured by friction within an aperture extending through the floor of the tin box, wherein the degassing valve is shown with the valve seat and disk in the sealed position; and

[0022]FIG. 3 is a cross-section of the degassing valve showing the disk and valve seat with the disk in the open position.

DETAILED DESCRIPTION OF THE INVENTION

[0023] Referring to FIG. 1, there is shown an example of a rigid container package 1, such as made of tin or metal or other rigid material, constructed in accordance with this invention. In the preferred embodiment, the package 1 comprises a tin box 3 having a pressure-equalizing one-way degassing valve 5 mounted in its base 7 or other surface (as will be described later) and a lid 9 which securely fits on and seals the box 3. The tin box 3 is preferably arranged to hold any particulate material e.g., coffee beans, ground coffee, dry pet food, chemicals, etc. Moreover, the tin box 3 is particularly suitable for holding large amounts of such materials, e.g., in excess of twenty-five pounds, although it can be used for packaging small amounts as well.

[0024] In the preferred embodiment, the tin box 3 is formed from a rigid material, such as tin, metal, etc., and comprises a front wall or panel 11, a rear wall or panel (not shown), two sidewalls or panels 13, 15, a top end portion 17, the lid 9, and the bottom wall or panel portion 7. The top end portion 17 of the package terminates and has lid 9 that fits securely on tin box 3, finishing off the overall appearance of the package. The bottom wall or panel or base end portion 7 forms the bottom of the package. The degassing valve 5 (in this drawing) is preferably mounted in the bottom wall or bottom panel 7, but the degassing valve 5 can be mounted on virtually any portion of the tin box 3, including the lid 9, rear wall, the front wall 11, or side walls 13, 15. The degassing valve 5 is preferably in communication with the interior of the tin box 3 regardless of its location. The valve 5 enables gasses, which may be produced by the particulate material(s) contained within the box 3, after it is hermetically sealed, to vent to the ambient air, without air gaining ingress into the tin box's 3 interior.

[0025] The front panel 11, rear panel, and the two side panels 13, 15 of the tin box 3 are preferably integral portions of a single sheet of tin, metal or other rigid container material. Particularly useful tin, metal or rigid container material for the tin box 3 is commercially available companies such as Royal Summit, Inc., of Modesto, Calif., the assignee of this invention. The lower wall or panel 7 of the tin box 3 is preferably sealed closed along a transverse, permanent seam line, closely adjacent the bottom edge. The permanent seam line is preferably formed using standard sealing techniques, such as that used by tin box factories around the world. The tin box 3 is preferably arranged to be hermetically sealed by bending the sheet together, which creates a permanent seal. The lid or top 9 is manufactured so that it mates with the tin body 3 and seals the package, thus isolating the contents of the package from the ambient atmosphere once it is hermetically sealed.

[0026] When the tin box 3 is filled and sealed, the particulate materials inside will be kept isolated from the ambient air by the tin box 3 and the application of the top or lid 9. The package can be readily stacked in multiples in a stable manner. Moreover, the weight of the stacked packages, plus the close conformance between the valve on one package, and the abutting wall of an adjacent package, can help effectively cover the valve to help maintain the hermetical seal and aesthetics of the package. Any gasses that are produced by the material within the package are nevertheless able to vent to the exterior in a normal manner (as will be described later) through valve 5.

[0027]FIG. 2 shows the valve 5 positioned inside an aperture 19 extending through a portion of the rigid container 3. In this embodiment, the aperture 19 is located on bottom wall or panel 7, although in other embodiments, it can be located virtually anywhere on box 3. The valve 5 preferably has an insert portion 21 that can be inserted and frictionally secured to the inside edge of aperture 19, and a flange 27 that can be placed over the exterior 25 of the wall or panel 7. This serves as the means by which the valve 5 is secured to the bottom wall 7 of the package 3, with flange 27 firmly resting on the outer surface of the package. The insert portion 21 preferably fits securely into the rigid container 3 via the aperture 19 that is made slightly smaller than the exterior of the insert portion 21, such that the insert portion 21 can be passed through the aperture 19, and the expanded flange portion 27 of the valve can then be allowed to firmly rest against the exterior 25 of the rigid container 3, wherein friction between the aperture 19 and insert portion 21 (resulting from an interference fit) helps to permanently seal the aperture 19 and adhere the valve 5 to the rigid container 3.

[0028] As can be seen in FIG. 2, the internal components of valve 5 comprise an upper cap portion 29 connected to a lower base member 30 (which includes the flange 27), with an electrometric, e.g., rubber, disk 31 positioned inside an interior compartment 35 formed between the cap portion 29 and base member 30. The disk can be made in any conventional material. The cap portion 29 and base member 30 are preferably adapted to be snapped and connected together by mating sections 32, 34, as shown, with disk 31 inside compartment 35 during assembly. A thin layer of oil 38, e.g., silicone oil is preferably provided inside compartment 35 on disk 31 adjacent valve seat 36, to help maintain disk 31 by tension in a sealed position inside compartment 35.

[0029] The “sealed position” is the one shown in FIG. 2, wherein disk 31 is positioned against valve seat 36. Disk 31 effectively covers and seals opening 37, which communicates between compartment 35 and interior of box 3. A filter member 33 is preferably provided on base member 30 on the interior side 24 of opening 37 relative to disk 31 to cover opening 37 and ensure that dust and other small particles from inside box 3, which can interfere with disk 31 and oil 38, and therefore, the operation of valve 5, cannot be introduced into compartment 35.

[0030] The valve 5 has two modes of operation. FIG. 2 shows valve 5 in its “closed or sealed” position, and FIG. 3 shows valve 5 in its “pressure release mode.” The second mode shown in FIG. 3 occurs when a pressure differential is applied to the valve 5 such that the pressure in the interior of box 3 is higher than the pressure on the exterior of the package. In this situation, valve 5 functions to equalize the interior and exterior pressures by allowing the higher internal pressure to break the elastic bond between the valve seat 36, silicone oil 38, and disk 31, allowing air to escape in the direction of arrows 40, through filter 33, base member's opening 37, around disk 31, and through a hole 39 in cap member 29.

[0031] Once sufficient air has been released out of the package to equalize the internal and external pressures, the disk 31 automatically returns to it normally flat, unflexed state, shown in FIG. 2. The surface tension of the silicone oil 38 then reseals the bond between the valve seat 36, and disk 31. Thus, valve 5 stops operating in the “pressure release” mode and begins operating again in the “closed or sealed” static equilibrium mode.

[0032] The “static equilibrium mode” of operation is shown in FIG. 2 and occurs when the interior package pressure and exterior package pressure are equal. In this situation the disk 31 remains sealed to valve seat 36 by the viscous nature of oil 38. In particular, the equal pressures maintain disk 31 in a flat, unflexed position, thus keeping valve 5 closed and impermeable to external, atmospheric gasses (e.g. Oxygen), moisture, or odors. In all cases, the walls of the package 3 remain smooth and non-bulging, as shown in FIG. 1.

[0033] As should be appreciated by those skilled in the art the subject invention provides a valve which allows a tin, metal or rigid container package to be substantially and hermetically sealed in order to protect the package's content against external gasses, e.g. atmospheric oxygen, moisture and odors during the large majority of time when internal and external package pressures are at an equilibrium. Moreover, the valve provides a viable means for releasing entrapped air in the package so that it can be stacked and transported with similarly constructed packages, effectively and economically, without the risk of rupturing. Thus, the subject invention enables the creation of an easy to handle, well shaped, aesthetically pleasing, and durable package by enabling the vacuum therein to be released during shipment and storage. 

What is claimed is:
 1. A container made of a substantially rigid material, such as tin or metal, comprising: an aperture extending through a wall or panel thereof, said aperture having a perimeter formed with a substantially rigid edge extended on said wall; a one way degassing valve extended at least partially into said aperture, providing communication between an interior and exterior of said container, said valve comprising: an insert portion extended into said aperture, wherein an exterior surface of said insert portion is in frictional engagement with said edge of said aperture; a flange portion extended on one end of said insert portion, said flange portion extending outward relative to said insert portion; and wherein said valve is adapted to allow gas to pass through in a first direction when the pressure differential between said interior and exterior of said container exceeds a predetermined amount, while substantially preventing gas from passing through said valve in a second direction opposite said first direction.
 2. The container of claim 1, wherein said aperture is formed slightly smaller than the exterior surface of said insert portion, such that with said insert portion extended into said aperture, friction between said edge of said aperture and said exterior surface of said insert portion can help to secure said valve to said wall.
 3. The container of claim 1, wherein said flange portion is firmly engaged against said wall of said container adjacent said aperture.
 4. The container of claim 1, wherein said valve is positioned on said container in a manner such that the flange portion is located on an exterior side of said wall, and said valve prevents the gas from passing in said second direction which is from the exterior to the interior of said container, and allows the gas to pass in said first direction which is from the interior to the exterior of said container, when pressure in the interior of said container exceeds the pressure in the exterior of said container.
 5. The container of claim 1, wherein said valve comprises a cap and base member, wherein an interior compartment is formed between the cap and base member, and a displacement member with a layer of viscous fluid is provided on a seat inside said compartment, wherein the displacement member remains on said seat to prevent gas from passing through said valve when the pressure in the interior and exterior of said container are substantially equal, but can be lifted from said seat to allow gas to pass through openings in said base member and said cap, when the predetermined pressure differential amount is exceeded.
 6. The container of claim 5, wherein the tension provided by said viscous fluid helps to keep said displacement member on said seat in a closed position, to keep said hole in said base member closed, until such time that the pressure differential exceeds the predetermined amount, wherein said displacement member can be partially separated from said seat, to enable said hole in said base member to be opened, and allow the gas to pass through said cap in said first direction.
 7. The container of claim 6, wherein a filter is provided to cover said hole in said base member.
 8. A valve for use in connection with an aperture formed in a substantially rigid wall, comprising: an insert portion adapted to be extended into said aperture, wherein an exterior surface of said insert portion is slightly larger in diameter than said aperture; a flange portion extended on one end of said insert portion, said flange portion extending outward relative to said insert portion; and wherein said valve comprises a cap and base member, wherein an interior compartment is formed between said cap and base member, and a displacement member with a layer of viscous fluid is provided on a seat inside said compartment, wherein said displacement member is adapted to enable the gas to pass in said first direction, through holes in said base member and said cap, when a predetermined pressure differential is exceeded, and prevents the gas from passing through said valve in said second direction.
 9. The valve of claim 8, wherein the tension provided by said viscous fluid helps to keep said displacement member on said seat in a closed position, to close said hole in said base member, until such time that the pressure differential exceeds the predetermined amount, wherein said displacement member can be partially separated from said seat, to enable said hole in said base member to be opened, and allow the gas to pass through said cap in said first direction.
 10. The valve of claim 9, wherein a filter is provided to cover said hole in said base member.
 11. A method of securing a valve to a rigid wall of a container, comprising: forming an aperture in said wall having a predetermined size; providing an insert portion adapted to be extended into said aperture, wherein an exterior surface of said insert portion is adapted to be slightly larger in size than said aperture; providing a flange portion extended on one end of said insert portion, said flange portion extending outward relative to said insert portion; and inserting said insert portion into said aperture, wherein the friction between the exterior surface of said insert portion and inside edge of said aperture help to maintain said valve in a substantially fixed position on said wall.
 12. The method of claim 11, wherein said valve is inserted into said aperture until the flange rests against the wall of said container.
 13. The method of claim 11, wherein the insert portion is inserted into said aperture from an exterior of said container, and said valve is designed to enable gas to pass from an interior to an exterior of said container, when a predetermined pressure differential exists between said interior and exterior of said container, and to prevent gas from passing from said exterior to said interior of said container. 